I'm new to this forum but I've been reading a lot of the great info on this site for a few months. I finally decided to get serious about designing and building a dolly. My goal is a low cost, relatively light weight dolly that I can take backpacking. I got a lot of inspiration from the dolly v1 prototype. Here is my design so far.
The rail is 80/20, and the slider is their linear bearing system. I am thinking of getting a shorter piece of rail for backpacking and a longer (72" or so) piece for more travel.
*15 Series 1.5" x 3.0" Lite Smooth T-Slot Aluminum Extrusion, Part # 1530
*15 Series Double Flange Linear Bearing, Part #6824
Here is my shopping list from SDP/SI:
The power transmission is with a 5mm HTD pitch, 9mm wide timing belt. The motor side has a 12-tooth pulley. The free end is just two flat aluminum pieces with bearings and a shaft. I am still working on a good way to attach the timing belt to the slider and add quick release capability.
My electronics are an Arduino, DFRobot LCD Shield and an EasyDriver. I am hoping to run miniE (right here!)
I am planning on using the Anaheim Automation 17Y-302S-LW4. Stepper motors still confuse me, but assuming the ideal torque of 61 oz-in, with the 12-tooth pulley (.75in pitch diameter) that works out to just over 10 lbs of pull. I am fine with even half of that, as right now I'm using an XSi and Sigma 10-20.
Any suggestions / problems that you guys can see? My main worry is the stepper not being powerful enough. I want to avoid using a geared motor if possible, but I may have to?